I've been wondering about this myself. The Snipe only had a short operational span during WWI since it arrived at squadrons only a couple of months before the armistice (similar to the DVIII). So there wouldn't have been much time to acquire much "usage wear." I could, however, give it more of a back from today's mission look. I might also give it a bit of a rub down with a paper towel with some semi-dried black paint which would have the effect of blending it all together and giving it a "weightier" look. This is what I did on my Legionnaire (though it a bit of a heavy-handed way).